Effect of Phytic Acid, Tin Oxide and Graphite Incorporation in Polyaniline Semiconductive Ink

Abstract

Enhanced electrical conductivity and pressure sensing functionalities of phytic acid-doped polyaniline ink (PPhyA) incorporated with SnO2 (PPhyAS) and graphite flakes (PPhyAG) as reported in our previous article, encouraged us to explore the electrical conduction mechanism and associated optical properties. In order to realize the enhanced electrical conduction in the reported inks, detailed studies were carried out in our research described here in comparison with normal HCl-doped polyaniline (PANI). This can be attributed to the formation of a highly ordered molecular arrangement with high crystallinity, a change in the hopping pathway between two adjacent molecules and the hopping activation energy of the PANI chain in the phytic acid-doped ink systems. Optical parameters, such as absorption edge, Urbach energy, refractive index, extinction coefficient, optical conductivity and optical dielectric constants, were estimated from the result of UV-Vis spectroscopy. The results of these studies showed enhancement of the optical properties of the phytic acid-doped ink systems (PPhyA, PPhyAS and PPhyAG) in the low photon energy range as compared to HCl-doped PANI. Phytic acid-doped ink systems are paintable on a variety of flexible surfaces, such as paper and plastics. Hence, we suggest that the phytic acid-doped ink systems have a great potential for developing flexible and foldable circuitry for infrared optics and remote sensing.